The present embodiments relate to medical imaging.
Nuclear medicine uses radiation emission to acquire images that show the function and/or physiology of organs, bones or tissues of the body. Radiopharmaceuticals are introduced into the body by injection or ingestion. The radiopharmaceuticals are attracted to specific organs, bones, or tissues of interest. The radiopharmaceuticals cause gamma photons to emanate from the body, which are then captured by detectors. One or more detectors are used to detect the emitted gamma photons, and the information collected from the detector(s) is processed to calculate the position of origin of the emitted photon from the source (i.e., the body organ or tissue under study). The interactions of the gamma photons with scintillation crystals of the detector(s) produce flashes of light captured by optical sensors of the detector(s). The accumulation of a large number of emitted gamma positions allows an image of the organ or tissue under study to be displayed.
In single photon emission computed tomography (SPECT), a collimator is placed in front a scintillation crystal to allow only gamma rays aligned with the holes of the collimator to pass through to the detector. The line along which the gamma emission occurred can thus be inferred. Mathematical procedures are used to solve the set of equations and reconstruct images from the raw scan data. Reconstruction methods may be non-iterative procedures (e.g., filtered back projection) or iterative procedures (e.g., maximum likelihood expectation maximization and minimization of an objective function).
Clinical studies are undertaken to determine the best reconstruction method, to determine parameters for new methods under development, or to improve the performance of existing reconstruction procedures. For example, clinical studies are directed to optimizing reconstruction procedures for imaging certain tissue regions or organs, such as the brain. Often, clinical studies are structured as collaborative efforts involving individuals at one or more clinical sites at which the scan data is collected, as well as individuals remotely located from the clinical sites. These collaborative efforts are time consuming to coordinate, making collection of information difficult.